1 //===-- llvm/MC/WinCOFFStreamer.cpp -----------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains an implementation of a Win32 COFF object file streamer.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "WinCOFFStreamer"
16 #include "llvm/MC/MCObjectStreamer.h"
17 #include "llvm/MC/MCContext.h"
18 #include "llvm/MC/MCSection.h"
19 #include "llvm/MC/MCSymbol.h"
20 #include "llvm/MC/MCExpr.h"
21 #include "llvm/MC/MCValue.h"
22 #include "llvm/MC/MCAssembler.h"
23 #include "llvm/MC/MCAsmLayout.h"
24 #include "llvm/MC/MCCodeEmitter.h"
25 #include "llvm/MC/MCSectionCOFF.h"
26 #include "llvm/Target/TargetRegistry.h"
27 #include "llvm/Target/TargetAsmBackend.h"
28 #include "llvm/ADT/StringMap.h"
30 #include "llvm/Support/COFF.h"
31 #include "llvm/Support/Debug.h"
32 #include "llvm/Support/ErrorHandling.h"
33 #include "llvm/Support/raw_ostream.h"
37 class WinCOFFStreamer : public MCObjectStreamer {
39 MCSymbol const *CurSymbol;
41 WinCOFFStreamer(MCContext &Context,
42 TargetAsmBackend &TAB,
46 void AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
47 unsigned ByteAlignment, bool External);
49 // MCStreamer interface
51 virtual void EmitLabel(MCSymbol *Symbol);
52 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag);
53 virtual void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value);
54 virtual void EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute);
55 virtual void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue);
56 virtual void BeginCOFFSymbolDef(MCSymbol const *Symbol);
57 virtual void EmitCOFFSymbolStorageClass(int StorageClass);
58 virtual void EmitCOFFSymbolType(int Type);
59 virtual void EndCOFFSymbolDef();
60 virtual void EmitELFSize(MCSymbol *Symbol, const MCExpr *Value);
61 virtual void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
62 unsigned ByteAlignment);
63 virtual void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size);
64 virtual void EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
65 unsigned Size,unsigned ByteAlignment);
66 virtual void EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
67 uint64_t Size, unsigned ByteAlignment);
68 virtual void EmitBytes(StringRef Data, unsigned AddrSpace);
69 virtual void EmitValue(const MCExpr *Value, unsigned Size,
71 virtual void EmitGPRel32Value(const MCExpr *Value);
72 virtual void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
73 unsigned ValueSize, unsigned MaxBytesToEmit);
74 virtual void EmitCodeAlignment(unsigned ByteAlignment,
75 unsigned MaxBytesToEmit);
76 virtual void EmitValueToOffset(const MCExpr *Offset, unsigned char Value);
77 virtual void EmitFileDirective(StringRef Filename);
78 virtual void EmitDwarfFileDirective(unsigned FileNo,StringRef Filename);
79 virtual void EmitInstruction(const MCInst &Instruction);
80 virtual void Finish();
82 } // end anonymous namespace.
84 WinCOFFStreamer::WinCOFFStreamer(MCContext &Context,
85 TargetAsmBackend &TAB,
88 : MCObjectStreamer(Context, TAB, OS, &CE)
92 void WinCOFFStreamer::AddCommonSymbol(MCSymbol *Symbol, uint64_t Size,
93 unsigned ByteAlignment, bool External) {
94 assert(!Symbol->isInSection() && "Symbol must not already have a section!");
96 std::string SectionName(".bss$linkonce");
97 SectionName.append(Symbol->getName().begin(), Symbol->getName().end());
99 MCSymbolData &SymbolData = getAssembler().getOrCreateSymbolData(*Symbol);
101 unsigned Characteristics =
102 COFF::IMAGE_SCN_LNK_COMDAT |
103 COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA |
104 COFF::IMAGE_SCN_MEM_READ |
105 COFF::IMAGE_SCN_MEM_WRITE;
107 int Selection = COFF::IMAGE_COMDAT_SELECT_LARGEST;
109 const MCSection *Section = MCStreamer::getContext().getCOFFSection(
110 SectionName, Characteristics, Selection, SectionKind::getBSS());
112 MCSectionData &SectionData = getAssembler().getOrCreateSectionData(*Section);
114 if (SectionData.getAlignment() < ByteAlignment)
115 SectionData.setAlignment(ByteAlignment);
117 SymbolData.setExternal(External);
119 Symbol->setSection(*Section);
121 if (ByteAlignment != 1)
122 new MCAlignFragment(ByteAlignment, 0, 0, ByteAlignment, &SectionData);
124 SymbolData.setFragment(new MCFillFragment(0, 0, Size, &SectionData));
127 // MCStreamer interface
129 void WinCOFFStreamer::EmitLabel(MCSymbol *Symbol) {
130 // TODO: This is copied almost exactly from the MachOStreamer. Consider
131 // merging into MCObjectStreamer?
132 assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
133 assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
134 assert(CurSection && "Cannot emit before setting section!");
136 Symbol->setSection(*CurSection);
138 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
140 // FIXME: This is wasteful, we don't necessarily need to create a data
141 // fragment. Instead, we should mark the symbol as pointing into the data
142 // fragment if it exists, otherwise we should just queue the label and set its
143 // fragment pointer when we emit the next fragment.
144 MCDataFragment *F = getOrCreateDataFragment();
145 assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
147 SD.setOffset(F->getContents().size());
150 void WinCOFFStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
151 llvm_unreachable("not implemented");
154 void WinCOFFStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
155 // TODO: This is exactly the same as MachOStreamer. Consider merging into
157 getAssembler().getOrCreateSymbolData(*Symbol);
158 AddValueSymbols(Value);
159 Symbol->setVariableValue(Value);
162 void WinCOFFStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
163 MCSymbolAttr Attribute) {
165 case MCSA_WeakReference:
166 getAssembler().getOrCreateSymbolData(*Symbol).modifyFlags(
167 COFF::SF_WeakReference,
168 COFF::SF_WeakReference);
172 getAssembler().getOrCreateSymbolData(*Symbol).setExternal(true);
176 llvm_unreachable("unsupported attribute");
181 void WinCOFFStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
182 llvm_unreachable("not implemented");
185 void WinCOFFStreamer::BeginCOFFSymbolDef(MCSymbol const *Symbol) {
186 assert(CurSymbol == NULL && "EndCOFFSymbolDef must be called between calls "
187 "to BeginCOFFSymbolDef!");
191 void WinCOFFStreamer::EmitCOFFSymbolStorageClass(int StorageClass) {
192 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
193 assert((StorageClass & ~0xFF) == 0 && "StorageClass must only have data in "
196 getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
197 StorageClass << COFF::SF_ClassShift,
201 void WinCOFFStreamer::EmitCOFFSymbolType(int Type) {
202 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
203 assert((Type & ~0xFFFF) == 0 && "Type must only have data in the first 2 "
206 getAssembler().getOrCreateSymbolData(*CurSymbol).modifyFlags(
207 Type << COFF::SF_TypeShift,
211 void WinCOFFStreamer::EndCOFFSymbolDef() {
212 assert(CurSymbol != NULL && "BeginCOFFSymbolDef must be called first!");
216 void WinCOFFStreamer::EmitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
217 llvm_unreachable("not implemented");
220 void WinCOFFStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
221 unsigned ByteAlignment) {
222 AddCommonSymbol(Symbol, Size, ByteAlignment, true);
225 void WinCOFFStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size) {
226 AddCommonSymbol(Symbol, Size, 1, false);
229 void WinCOFFStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
230 unsigned Size,unsigned ByteAlignment) {
231 llvm_unreachable("not implemented");
234 void WinCOFFStreamer::EmitTBSSSymbol(const MCSection *Section, MCSymbol *Symbol,
235 uint64_t Size, unsigned ByteAlignment) {
236 llvm_unreachable("not implemented");
239 void WinCOFFStreamer::EmitBytes(StringRef Data, unsigned AddrSpace) {
240 // TODO: This is copied exactly from the MachOStreamer. Consider merging into
242 getOrCreateDataFragment()->getContents().append(Data.begin(), Data.end());
245 void WinCOFFStreamer::EmitValue(const MCExpr *Value, unsigned Size,
246 unsigned AddrSpace) {
247 assert(AddrSpace == 0 && "Address space must be 0!");
249 // TODO: This is copied exactly from the MachOStreamer. Consider merging into
251 MCDataFragment *DF = getOrCreateDataFragment();
253 // Avoid fixups when possible.
255 if (AddValueSymbols(Value)->EvaluateAsAbsolute(AbsValue)) {
256 // FIXME: Endianness assumption.
257 for (unsigned i = 0; i != Size; ++i)
258 DF->getContents().push_back(uint8_t(AbsValue >> (i * 8)));
260 DF->addFixup(MCFixup::Create(DF->getContents().size(),
261 AddValueSymbols(Value),
262 MCFixup::getKindForSize(Size)));
263 DF->getContents().resize(DF->getContents().size() + Size, 0);
267 void WinCOFFStreamer::EmitGPRel32Value(const MCExpr *Value) {
268 llvm_unreachable("not implemented");
271 void WinCOFFStreamer::EmitValueToAlignment(unsigned ByteAlignment,
274 unsigned MaxBytesToEmit) {
275 // TODO: This is copied exactly from the MachOStreamer. Consider merging into
277 if (MaxBytesToEmit == 0)
278 MaxBytesToEmit = ByteAlignment;
279 new MCAlignFragment(ByteAlignment, Value, ValueSize, MaxBytesToEmit,
280 getCurrentSectionData());
282 // Update the maximum alignment on the current section if necessary.
283 if (ByteAlignment > getCurrentSectionData()->getAlignment())
284 getCurrentSectionData()->setAlignment(ByteAlignment);
287 void WinCOFFStreamer::EmitCodeAlignment(unsigned ByteAlignment,
288 unsigned MaxBytesToEmit) {
289 // TODO: This is copied exactly from the MachOStreamer. Consider merging into
291 if (MaxBytesToEmit == 0)
292 MaxBytesToEmit = ByteAlignment;
293 MCAlignFragment *F = new MCAlignFragment(ByteAlignment, 0, 1, MaxBytesToEmit,
294 getCurrentSectionData());
295 F->setEmitNops(true);
297 // Update the maximum alignment on the current section if necessary.
298 if (ByteAlignment > getCurrentSectionData()->getAlignment())
299 getCurrentSectionData()->setAlignment(ByteAlignment);
302 void WinCOFFStreamer::EmitValueToOffset(const MCExpr *Offset,
303 unsigned char Value) {
304 llvm_unreachable("not implemented");
307 void WinCOFFStreamer::EmitFileDirective(StringRef Filename) {
308 // Ignore for now, linkers don't care, and proper debug
309 // info will be a much large effort.
312 void WinCOFFStreamer::EmitDwarfFileDirective(unsigned FileNo,
313 StringRef Filename) {
314 llvm_unreachable("not implemented");
317 void WinCOFFStreamer::EmitInstruction(const MCInst &Instruction) {
318 for (unsigned i = 0, e = Instruction.getNumOperands(); i != e; ++i)
319 if (Instruction.getOperand(i).isExpr())
320 AddValueSymbols(Instruction.getOperand(i).getExpr());
322 getCurrentSectionData()->setHasInstructions(true);
324 MCInstFragment *Fragment =
325 new MCInstFragment(Instruction, getCurrentSectionData());
327 raw_svector_ostream VecOS(Fragment->getCode());
329 getAssembler().getEmitter().EncodeInstruction(Instruction, VecOS,
330 Fragment->getFixups());
333 void WinCOFFStreamer::Finish() {
334 MCObjectStreamer::Finish();
339 MCStreamer *createWinCOFFStreamer(MCContext &Context,
340 TargetAsmBackend &TAB,
343 return new WinCOFFStreamer(Context, TAB, CE, OS);